In a paper published in the journal Applied Physics Letters, the researchers from the University of Leeds and Sheffield University examined the role of domain walls (DWs) in magnetic nanowires for use in so-called racetrack memory, which is a non-volatile memory device being developed by IBM under the direction of Stuart Parkin. DWs are able to represent binary data by taking into account the orientations of magnetically bi-stable domains that have been separated by them.

The UK researchers turned to racetrack memory as a way to eliminate moving parts on hard disk drives in which sensors scan a disk surface while it spins. While solid-state memory has, of course, already been achieved with flash memory, the UK team wanted to see if they could devise a memory that was more reliable, cheaper and faster than flash.

Racetrack memory is attractive because it moves data through magnetic nanowires on which data runs up and down like racecars—thus the name. However, to get the race cars (the data) to run up and down the track (the nanowires) the system depends on magnetic fields or electric currents and this produces a lot of heat and reduces power efficiency.

This is why the researchers turned to surface acoustic waves.

“The key advantage of surface acoustic waves in this application is their ability to travel up to several centimetres without decaying, which at the nano-scale is a huge distance,” said Tom Hayward, a research fellow at the University of Sheffield, in a press relese. “Because of this, we think a single sound wave could be used to “sing” to large numbers of nanowires simultaneously, enabling us to move a lot of data using very little power. We’re now aiming to create prototype devices in which this concept can be fully tested.”